Re: [PATCH] Devirtualization dump functions fix

[Richard Biener <richard dot guenther at gmail dot com>]

On Thu, Jun 26, 2014 at 3:43 PM, Martin LiÅka <mliska@suse.cz> wrote:
>
> On 06/26/2014 03:20 PM, Richard Biener wrote:
>>
>> On Thu, Jun 26, 2014 at 3:01 PM, Martin LiÅka <mliska@suse.cz> wrote:
>>>
>>> Hello,
>>>     I encountered similar issue to PR ipa/61462 where location_t locus =
>>> gimple_location (e->call_stmt) is called for e->call_stmt == NULL
>>> (Firefox
>>> with -flto -fdump-ipa-devirt). So that, I decided to introduce new
>>> function
>>> that is called for all potentially unsafe locations. I am wondering if a
>>> newly added function can be added in more seamless way (without playing
>>> with
>>> va_list and ATTRIBUTE_PRINTF stuff)?
>>>
>>> Bootstrapped and regtested on x86_64-unknown-linux-gnu.
>>
>> Hmm, I don't like that very much - dump_printf_loc_for_stmt still implies
>> stmt is not NULL.  So you could have "fixed" gimple_location as well.
>> I suppose dump_printf_loc already does sth sane with UNKNOWN_LOCATION.
>>
>> Richard.
>
> Hi,
>    you are right that it is quite complex change.
>
> Do you mean this one line change can be sufficient ?
> diff --git a/gcc/gimple.h b/gcc/gimple.h
> index ceefbc0..954195e 100644
> --- a/gcc/gimple.h
> +++ b/gcc/gimple.h
> @@ -1498,7 +1498,7 @@ gimple_set_block (gimple g, tree block)
>  static inline location_t
>  gimple_location (const_gimple g)
>  {
> -  return g->location;
> +  return g ? g->location : UNKNOWN_LOCATION;
>  }
>
>  /* Return pointer to location information for statement G.  */
>
> I will double-check if it solves the problem ;)

Well yes - it is of course similar broken in spirit but at least a lot
simpler ;)  I'd put a comment there why we do check g for NULL.

Thanks,
Richard.

> Martin
>
>
>>
>>> Thanks,
>>> Martin
>>>
>>>      ChangeLog:
>>>
>>>      2014-06-26  Martin Liska  <mliska@suse.cz>
>>>
>>>          * include/ansidecl.h: New collection of
>>> ATTRIBUTE_NULL_PRINTF_X_0
>>>          defined.
>>>
>>>      gcc/ChangeLog:
>>>
>>>      2014-06-26  Martin Liska  <mliska@suse.cz>
>>>
>>>          * dumpfile.h: New function dump_printf_loc_for_stmt.
>>>          * dumpfile.c: Implementation added.
>>>          (dump_vprintf): New function.i
>>>          * cgraphunit.c: dump_printf_loc_for_stmt usage replaces
>>>          dump_printf_loc.
>>>          * gimple-fold.c: Likewise.
>>>          * ipa-devirt.c: Likewise.
>>>          * ipa-prop.c: Likewise.
>>>          * ipa.c: Likewise.
>>>          * tree-ssa-pre.c: Likewise.
>>>
>>>
>>>
>>>
>